Considering it is just a game why do some role-players become emotional or unusually sensitive when interacting with other players in the same game?
Some people are naturally emotional so it does not matter what they are involved in they will be emotional about it. Same goes for sensitivity. Then there are players that really put their heart into a game and truly role-play. Its kind of how actors get so much into a role that they end up needing time off or a psychologist to make sure they're back with reality.